Non-structural injection grouts with reduced water content: Changes induced by the partial substitution of water with alcohol

Conventional grouting – used to stabilise delaminated plaster – typically involves the use of water as suspension medium. Water can be dangerous when water-sensitive original materials are present and can cause the solubilisation of salts, leading to their re-crystallisation on drying. Ethyl alcohol is a less effective solvent for soluble salts and generally does not affect the original materials. This is the reason why it was used as a partial substitute for water in grout preparations in the present research. Three water–ethyl alcohol-based grouts were compared with the correspondent water-based grout. The working properties and performance characteristics of the injection grouts with reduced water content were measured to assess their suitability for use on historic plasters.